fish or cut bait?

OK - so here's the dilemma - when do you know to cut bait? I mean, let's say you've been out with a guy 3 or 4 or 5 times (and after the initial fun newness has rubbed off), and you're not feeling attracted to said guy but you enjoy their company...? Oh, I know the answer.

Crap - this has happened with the last three guys I've dated and I don't want to get stuck in some sort of ice-princess-rut. And yes, I have tried drinking more.